We were out in our Crablandia plots at the Secrest Arboretum of OSU’s Ohio Agricultural Research and Development Center in Wooster today. One mission was to check for bacterial fireblight disease on the 76 crabapple taxa in our replicated, randomized plot. This spring we had heard of and seen some fireblight, on crabapples and other related rosaceous plants such as pears elsewhere, and we have susceptible crabapples in the trials so why not here? Yet, cultivar after cultivar, early blooming and late blooming types - no fireblight. Wait, wait, we see one shoot with the tell-tale shepherd’s...

Reports of branch die back in many trees are coming into the Medina Extension Office from around the county.  These brown patches are most likely the result of periodical cicadas laying eggs in the tender branches of trees.  Cicadas prefer laying their eggs in young twigs about 1/4 to 1/2 inch in diameter.  To lay their eggs, cicada stab a needle-like ovipositor into the branch that can cause these tender twigs to break, wither, and die.  The resulting symptom is browning leaves at branch tips known as "flags" or "flagging".  While larger trees have enough foliage to withstand tip dieback...

This digital image of dogwood arrived with the e-mailer asking if the problem was leaf scorch.   Damage seemed too great and too complete to be simple leaf scorch due to some transient heat stress. Further information indicated that someone had suggested that the plant needed potash and the e-mailer applied it and then asked if too much could be applied.  Well, yes. As with anything, even something as useful as fertilizer, “the dose makes the poison.”

The sender had applied 2 pounds of a 6 pound bag of a consumer-product potash (0-0-60) fertilizer. So at 2 pounds...

Earlier this week, Eric Richer (OSU Extension, Fulton County) sent me an image of a maple with almost all of the branches covered with Cottony Maple Scale females that were extruding their elongated, white, cottony ovisacs.  The oval-shaped dark brown females remained highly visible with their ovisacs peeking out from beneath their bodies.  The ovisacs expand to look like 1/4" diameter cotton balls on the branches of their host plants.  The scale has a very wide host range which includes their namesake host as well as ash, basswood/linden, black locust, dogwood, elm, euonymus, hackberry,...

Northern Masked Chafer (Cyclocephala borealis) and Southern Masked Chafer (C. lurida) adults are appearing around porchlights at night in southern Ohio.  It is common for people to assume that white grubs found beneath turfgrass in Ohio are Japanese beetle (Popillia japonica) grubs.  This is no longer a safe bet.  Japanese beetles have largely been replaced by these two chafers as the dominant "white grub producing" beetles in many areas of Ohio including the southern part of the state.  Indeed, I asked an experienced lawn care company last season to collect...

I received several images of white oak leaves from a homeowner who wanted to know why the leaves appeared bleached.  The culprit was Oak Lace Bug (Corythucha arcuata).  This lace bug lives on the undersides of oak leaves where they use their piercing/sucking mouth parts to suck juices from the leaves.  As with all lace bugs, their feeding produces tiny yellow or whitish leaf spots (stippling) that may coalesce to produce large, white patches on the upper leaf surface.  Eventually, the damage becomes yellow-to-copper colored and the overall damage can produce early leaf drop....

White pine weevil (Pissodes strobi) larval feeding damage is now becoming very evident in southern Ohio.  This means that localized weevil populations may be reduced by removing and destroying infested conifer terminals.  Overwintered females deposit eggs in early spring in the terminals of a wide range of conifers including Douglas-fir, all spruces, as well as Scotch, jack, red, pitch, and eastern white pines.  After the eggs hatch, the resulting white, legless, slightly curved, grub-like larvae tunnel downward just beneath the bark feeding on phloem tissue until pupation.  The...

One of my all-time favorite plant galls is the appropriately named Translucent Oak Gall.  The galls are produced by the gall-wasp, Amphibolips nubilipennis (family Cynipidae).  They arise from a leaf vein on the lower leaf surface and measure around 1/2 - 3/4" in diameter.  Their shape and color causes them to strongly resemble tiny, pink balloons or pink grapes hanging beneath the leaves of red, scarlet, and black oaks. 

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Recently in Northeast Ohio, the fungal disease known as Orange Rust is beginning to rear its unique, but strange symptoms on brambles, which are also known as cane berries.  Specifically, this fungus most often infects black and purple raspberries and sometimes is found on thornless blackberries, but is not known to infect red raspberries.

For me personally, this is the first time in my 24 years as an Extension Educator, that I have seen this disease on thornless blackberries.  Most often, this fungus is evident on either thorned blackberries or purple raspberries.  It is...

On June 18 I sent a byglalert about maple anthracnose diagnosed earlier this spring. The plant disease symptoms (see below) for that byglalert item included discolored blotches on the foliage which coalesced along leaf veins. The sample above for this alert today, sent from OSU Extension in Morrow County, show symptoms of leaf discoloration between the veins. This is the classic difference between physiological leaf scorch (this case) and anthracnose fungal disease (the previous case). The difference is all in the details. Physiological leaf scorch can be caused by many...